以下我們使用一個(gè)很簡(jiǎn)單的共振器范例模型進(jìn)行功能示范
此范例將會(huì)示范如何使用GLAD。我們將使用resonator.inp這個(gè)檔案示范共振器。即使使用者對(duì)共振器不感興趣，這個(gè)范例也將會(huì)展示在GALD中解決問題的幾個(gè)重要步驟：
初始化計(jì)算機(jī)數(shù)組及單位
選擇波長(zhǎng)
定義初始分布
使用宏進(jìn)行重復(fù)運(yùn)算
建立數(shù)據(jù)顯示計(jì)算結(jié)果
此共振器將使用半對(duì)稱的結(jié)構(gòu)進(jìn)行計(jì)算，由半徑50cm的球面鏡及平面鏡所組成。共振器的長(zhǎng)度為46cm。輸出將由平面鏡輸出。下表1顯示其結(jié)構(gòu)參數(shù)：
圖1-穩(wěn)定的共振器結(jié)構(gòu)。其光腰將會(huì)在平面鏡上形成，及其相曲率將與曲面鏡的理想模態(tài)曲率相同
為了簡(jiǎn)化討論，我們將忽略增益及形成bare-cavity分析。我們開始分析從準(zhǔn)備一個(gè)命令檔案如下：
variab/dec/int pass
macro/def reson/o
pass = pass + 1 # increment pass counter
prop 45 # propagate 45 cm.
mirror/sph 1 -50 # mirror of 50 cm. radius
clap/c/n 1 .14 # .14 cm. radius aperture
prop 45 # propagate 45 cm. along beam
mirror/flat 1 # flat mirror
variab/set Energy 1 energy # set variable to energy value
Energy = Energy - 1 # calculate energy difference
udata/set pass pass Energy # store energy differences
energy/norm 1 1 # renormalize energy
plot/l 1 xrad=.15 # make a plot at each pass
macro/end
array/set 1 64 # set array size
wavelength/set 0 1.064 # set wavelengths
units/set 1 .005 # set .005 cm sample spacing
resonator/name reson # set name of resonator macro
resonator/eigen/test 1 # find resonator properties
resonator/eigen/set 1 # set surrogate beam to eigen mode
clear 1 0 # clear the array
noise 1 1 # start from noise
energy/norm 1 1 # normalize energy
pass = 0 # initialize pass counter
reson/run 100 # run resonator 100 times
title Energy loss per pass
plot/watch plot1.plt # set plot name
plot/udata min=-.05 max=.0 # plot summary of eigenvalues
title diffraction mode shape
set/density 32 # set plot grid to 32 x 32
set/window/abs -.05 .05 -.05 .05 # set plot window
plot/watch plot2.plt # set plot name
plot/iso 1 # make an isometric plot
以下就對(duì)每一項(xiàng)指令來做介紹：
variab/dec/int pass
此行定義一整數(shù)變量叫pass。我們將使用pass來儲(chǔ)存數(shù)據(jù)，變量如果不清楚的定義為整數(shù)，將會(huì)被定義為實(shí)數(shù)變量。
macro/def reson/o
此行開始定義宏，就像是子程序或函式一樣。所有介于macro/def與macro/end之間的指令都將定義為宏。這些指令暫時(shí)不會(huì)被執(zhí)行。這些指令列將被放在MACLIB中留待以后使用。這些宏指令列將不需縮排。但使用縮排將會(huì)使這些指令更容易閱讀。 |
